Regulating Polaron Transport Regime via Heterojunction Engineering in Cove-Type Graphene Nanoribbons

Graphene nanoribbons (GNRs) are emerging materials inheriting excellent properties from graphene while potentially exhibiting semiconducting behavior. All these features sparked numerous efforts to insert GNRs in nanoelectronics. As a result, synthesis routes with atomic resolution are now a reality. Recently, the rise of heterojunction (HJ) engineering pushed even further the prospects, allowing the blending of different GNRs as building blocks. However, much of the potential behind it remains untouched for some junctions. In this work, the consequences of forming a cove-type GNR (CGNR) HJ by assembling specimens with borders of different zig-zag/armchair ratios are explored. The nanoribbons are simulated using the extended two-dimensional Su-Schrieffer-Heeger model with electron-phonon coupling. The findings show that manipulating the junction creates multiple routes for smooth monotonic gap tuning. Moreover, the changes in the hopping mechanism, mobility, and effective mass are reported leading to variations up to 10 000 cm(2) V-1 s(-1) and 0.425 m(e). This work reveals a pathway to expand the modularity of CGNRs through smooth control of the charge carrier's properties. Future applications can explore this feature to design devices with highly specific charge transport characteristics. The study also serves as theoretical background, potentially inspiring new tuning strategies in other GNRs.

Automated summary

Graphene nanoribbons (GNRs) have excellent properties and potential semiconducting behavior. Synthesis routes have been developed, and the rise of heterojunction (HJ) engineering allows blending different GNRs. This study explores the consequences of forming a cove-type GNR (CGNR) HJ by assembling specimens with different zig-zag/armchair ratios.